As compared with a conventional liquid crystal display (LCD), a self-emission display does not need a backlight module; therefore, the self-emission display may be made to be more lightweight and thin, larger viewing angle, and high response speed, and can be electrically saved. In various types of self-emission displays, it already becomes a mainstream of development to use a light-emitting diode (LED) as a light source.
Generally, a capacitive touch screen includes a display panel and a capacitive touch panel. A sensing manner of a capacitive touch panel may include self capacitance sensing and mutual capacitance sensing. As shown in FIG. 1A and FIG. 1B, FIG. 1A is a schematic diagram of self capacitance sensing of a capacitive touch panel. A control chip 502 charges a sampling capacitor 504 by using a driving signal 503. When a finger touches a covering glass 500, a coupling effect occurs between an electrode 501 and the finger, and charges on the sampling capacitor 504 are dispersed to make a potential of the sampling capacitor 504 decrease. When the control chip 502 senses the potential of the sampling capacitor 504 decreases below a threshold potential, the capacitive touch panel is regarded as sensing a touch control event. In another aspect, FIG. 1B is a schematic diagram of mutual capacitance sensing of a capacitive touch panel. As compared with the touch panel in FIG. 1A, the touch panel in FIG. 1B has two electrodes 511, 512. The electrode 511 is used to receive a scanning signal 514 output from a drive buffer apparatus 513, and the electrode 512 is used to generate a sensing signal. When a finger touches the covering glass 510, a coupling effect occurs between the electrode 511 and the finger, so that a capacitance between the electrode 511 and the electrode 512 changes. In this way, the electrode 512 generates a sensing signal accordingly to localize where to be touched.
However, if the display panel is equipped with the capacitive touch panel (that is, the display panel is attached externally to the capacitive touch panel), multiple layers of glass are needed, which greatly increases the thickness of a capacitive touch screen. Moreover, a process of a conventional capacitive touch screen is more complex than that of a common display panel without touch control, and a yield of the conventional capacitive touch screen is also relatively low. Therefore, how to integrate a touch display panel (that is, a display panel is equipped (in cell) with a touch panel (electrode)) to provide a relatively simple process and a thinner overall thickness is one of the important development topics at present.